Balancing circuit, balancing method, electronic device, battery management system and vehicle

Abstract

Disclosed are a vehicle and an electronic device, the vehicle comprising a battery management system, the battery management system comprising a balancing circuit, and the electronic device implementing a battery balancing method. The balancing circuit comprises a charging and discharging module, a switch module and a controller. The charging and discharging module is connected to a battery pack, and is used for controlling the on / off of a target charging and discharging channel. A first end of the switch module is separately connected to connection points, and a second end is connected to the charging and discharging module; and the switch module is used for controlling a target connection point to be connected to the charging and discharging module. The controller is connected to the charging and discharging module and the switch module, and is used for determining the target connection point on the basis of the total voltage of the battery pack and the actual voltage at each connection point, controlling the switch module on the basis of the target connection point, and controlling the charging and discharging module on the basis of the actual voltage at the target connection point, such that battery cells in the battery pack divided into two parts on the basis of the target connection point are charged and discharged.

Description

Balancing circuit, balancing method, electronic device, battery management system and vehicle

[0001] Cross-reference to Related Applications

[0002] The present application claims priority to the Chinese patent application No. 202410831832.1, filed on June 26, 2024, entitled “Balancing circuit, balancing method, electronic device, battery management system and vehicle”, the whole content of which is incorporated herein by reference. TECHNICAL FIELD

[0003] The present disclosure relates to the technical field of battery management, and in particular to a balancing circuit, a battery balancing method, an electronic device, a battery management system and a vehicle. BACKGROUND

[0004] In the related art, in the fields of electric vehicles and energy storage systems, a battery pack, as a core component of energy storage, is composed of multiple battery cells connected in series. However, during use, due to the small differences between battery cells, such as unmatched internal resistance, capacity differences, etc., some battery cells may charge or discharge faster than other battery cells, which may lead to energy imbalance between battery cells in the battery pack. This energy imbalance may affect the service life and performance of the battery pack.

[0005] DISCLOSURE

[0006] The present disclosure aims to at least solve one of the technical problems existing in the prior art. To this end, one object of the present disclosure is to provide a balancing circuit which can effectively transfer energy between battery cells in two parts divided by a target connection point, achieving energy balancing between battery cells in two parts in the battery pack, effectively avoiding overcharging or overdischarging of some battery cells in the battery pack, thereby improving the service life and performance of the battery pack, and the circuit structure is simple and the cost is low.

[0007] A second object of the present disclosure is to provide a battery balancing method.

[0008] A third object of the present disclosure is to provide an electronic device.

[0009] A fourth object of the present disclosure is to provide a battery management system.

[0010] A fifth object of the present disclosure is to provide a vehicle.

[0011] To achieve the above object, the equalization circuit according to an embodiment of the present disclosure is used for equalization of a battery pack, the battery pack includes a plurality of battery cells connected in series, and each two adjacent battery cells have a connection point, the equalization circuit includes a charge-discharge module, a first end of the charge-discharge module is connected to a positive terminal of the battery pack, a second end of the charge-discharge module is connected to a negative terminal of the battery pack, and the charge-discharge module is used for controlling a target charge-discharge channel; a switch module, a first end of the switch module is connected to each connection point respectively, a second end of the switch module is connected to a third end of the charge-discharge module, and the switch module is used for controlling a target connection point to be connected to the third end of the charge-discharge module; and a controller, the controller is connected to the charge-discharge module and the switch module, and is used for determining the target connection point according to a total voltage of the battery pack and an actual voltage at each connection point, controlling the switch module according to the target connection point, and controlling the charge-discharge module according to the actual voltage at the target connection point, so that the battery cells in two parts of the battery pack divided by the target connection point perform charge-discharge.

[0012] According to the equalization circuit, the controller can determine the target connection point by monitoring the total voltage of the battery pack and the actual voltage at each connection point in real time, the target connection point can be a point most needing equalization operation, and the target connection point is used as a boundary to divide the battery pack into two parts. When the target connection point is determined, the controller can send an instruction to the switch module to connect the target connection point to the charge-discharge module. Meanwhile, the controller controls the charge-discharge module according to the actual voltage at the target connection point, so that the battery cells in two parts of the battery pack divided by the target connection point perform charge-discharge operation. That is, when the battery cells in one part perform discharge operation, the battery cells in the other part can receive the electric energy through the charge-discharge module, thereby completing the equalization cycle of discharging to charging of the battery pack. Through the circuit structure, energy can be effectively transferred between the battery cells in two parts divided by the target connection point, the equalization of the battery cells in two parts of the battery pack is achieved, the overcharging or overdischarging of some battery cells in the battery pack is effectively avoided, and the service life and performance of the battery pack are improved. In addition, the circuit structure is simple and the cost is low.

[0013] In some embodiments, the charge-discharge module includes a first inductor, a first end of the first inductor is connected to the positive terminal of the battery pack, and a second end of the first inductor is connected to the second end of the switch module, and the first inductor is used for performing charge-discharge when the actual voltage at the target connection point is less than an expected voltage.

[0014] In some embodiments, the charging and discharging module further comprises a first switch, a first end of the first switch is connected with a positive terminal of the battery pack, a second end of the first switch is connected with a first end of the first inductor, for being turned on when an actual voltage at the target connection point is less than the expected voltage, and being turned off when a current flowing through the target connection point reaches a current threshold.

[0015] In some embodiments, the charging and discharging module further comprises a first diode, a positive terminal of the first diode is connected with a negative terminal of the battery pack, a negative terminal of the first diode is connected with the first end of the first inductor and the second end of the first switch.

[0016] In some embodiments, the charging and discharging module further comprises a second inductor, a first end of the second inductor is connected with a negative terminal of the battery pack, a second end of the first inductor is connected with a second end of the second inductor and a second end of the switch module, for charging and discharging when an actual voltage at the target connection point is greater than the expected voltage.

[0017] In some embodiments, the charging and discharging module further comprises a second switch, a first end of the second switch is connected with a negative terminal of the battery pack, a second end of the second switch is connected with a first end of the second inductor, for being turned on when an actual voltage at the target connection point is greater than the expected voltage, and being turned off when a current flowing through the target connection point reaches a current threshold.

[0018] In some embodiments, the charging and discharging module further comprises a second diode, a positive terminal of the second diode is connected with the first end of the second inductor and the second end of the second switch, a negative terminal of the second diode is connected with a positive terminal of the battery pack.

[0019] In some embodiments, the first switch and the second switch are both high-frequency one-way electronic switches.

[0020] In some embodiments, the switch module comprises a plurality of first contacts, a plurality of the first contacts are respectively connected with a plurality of the connection points; a second contact, the second contact is connected with a third end of the charging and discharging module; and a controllable switch piece, a first end of the controllable switch piece is connected with the second contact, a control end of the controllable switch piece is connected with the controller, and a second end of the controllable switch piece is connected with the first contact connected with the target connection point in response to a balancing instruction of the controller.

[0021] In some embodiments, the switch module comprises a plurality of third switches, a first end of each of the plurality of third switches is connected to one of the connection points, a second end of each of the plurality of third switches is connected to the third end of the charge-discharge module, a control end of each of the third switches is connected to the controller, and the third switch connected to the target connection point is turned on in response to the balancing instruction of the controller.

[0022] In some embodiments, the third switch is a low-frequency bidirectional electronic switch.

[0023] To achieve the above object, the battery balancing method according to the second aspect of the present disclosure is used in the balancing circuit described in the above embodiments, and comprises: determining a target connection point according to the total voltage of the battery pack and the actual voltage at the connection point between each two adjacent battery cells; controlling the switch module of the balancing circuit according to the target connection point, so that the target connection point is connected to the charge-discharge module of the balancing circuit; and controlling the charge-discharge module according to the actual voltage at the target connection point, so that the battery cells in the two parts of the battery pack divided by the target connection point are charged and discharged.

[0024] According to the battery balancing method of the present disclosure, by monitoring the total voltage of the battery pack and the actual voltage at the connection point between each two adjacent battery cells in real time, the target connection point can be determined, which can be the point most in need of balancing operation and is used as a dividing line to divide the battery pack into two parts. After the target connection point is determined, the switch module of the balancing circuit is controlled according to the target connection point, so that the target connection point is connected to the charge-discharge module. Meanwhile, the controller controls the charge-discharge module according to the actual voltage at the target connection point, so that the battery cells in the two parts of the battery pack divided by the target connection point are charged and discharged. That is, when the battery cells in one part are discharged, the battery cells in the other part can receive the electric energy through the charge-discharge module, thereby completing the balancing cycle of discharging to charging of the battery pack. Through this method, energy can be effectively transferred between the battery cells in the two parts divided by the target connection point, achieving the balancing of the electric quantity between the battery cells in the two parts of the battery pack, effectively avoiding the overcharging or overdischarging of some battery cells in the battery pack, thereby improving the service life and performance of the battery pack.

[0025] In some embodiments, controlling the charge-discharge module according to the voltage at the target connection point comprises: when the actual voltage at the target connection point is less than the expected voltage, turning on the first switch of the charge-discharge module, so that the battery cells between the target connection point and the positive terminal of the battery pack are discharged.

[0026] In some embodiments, the controlling the charging and discharging module according to the actual voltage at the target connection point further includes: when the current flowing through the target connection point reaches a current threshold, controlling the first switch to be turned off to charge the battery cells between the target connection point and the negative terminal of the battery pack in the battery pack.

[0027] In some embodiments, the controlling the charging and discharging module according to the actual voltage at the target connection point includes: when the actual voltage at the target connection point is greater than a desired voltage, controlling a second switch of the charging and discharging module to be turned on to cause the battery cells between the target connection point and the negative terminal of the battery pack in the battery pack to be discharged.

[0028] In some embodiments, the controlling the charging and discharging module according to the actual voltage at the target connection point further includes: when the current flowing through the target connection point reaches a current threshold, controlling the second switch to be turned off to charge the battery cells between the target connection point and the positive terminal of the battery pack in the battery pack.

[0029] In some embodiments, the target connection point is a connection point in the battery pack with the largest absolute value of voltage difference between the actual voltage and the desired voltage, where the desired voltage is the voltage of the connection point in the equalization state of the battery pack.

[0030] In some embodiments, the desired voltage is a product value of the average voltage of the plurality of battery cells in the battery pack and the sequential number of the connection point, where the negative terminal of the battery pack is taken as the zero potential point, and the first connection point is taken as the connection point between the first battery cell and the second battery cell on the side of the negative terminal of the battery pack.

[0031] To achieve the above object, the electronic device of the third aspect of the present disclosure comprises: at least one processor; a memory communicatively connected to the at least one processor; the memory stores a computer program executable by the at least one processor, and the at least one processor executes the computer program to implement the battery equalization method described in the above embodiments.

[0032] The electronic device according to the embodiments of the present disclosure can effectively transfer energy between the two parts of battery cells divided by the target connection point by executing the computer program implementing the battery equalization method described in the above embodiments, so as to achieve the energy balance between the two parts of battery cells in the battery pack, effectively avoid the overcharging or overdischarging of part of the battery cells in the battery pack, and thus improve the service life and performance of the battery pack.

[0033] To achieve the above object, the battery management system of the fourth aspect of the present disclosure comprises: a collection circuit configured to collect the total voltage of the battery pack and the actual voltage at the connection point between each two adjacent battery cells; and the equalization circuit described in the above embodiments, which is connected to the collection circuit.

[0034] According to the battery management system of the present disclosure, the collection circuit is connected to the equalization circuit. By collecting the total voltage of the battery pack and the actual voltage at the connection point between each two adjacent battery cells, the target connection point can be determined, which is the point most in need of equalization operation, and is used as a demarcation line to divide the battery pack into two parts. The switch module of the equalization circuit is controlled according to the target connection point, so that the target connection point is connected to the charge-discharge module of the equalization circuit. The charge-discharge module is controlled according to the actual voltage at the target connection point, so that the two parts of battery cells divided by the target connection point in the battery pack are subjected to charge-discharge operation. That is, when a part of the battery cells is subjected to discharge operation, another part of the battery cells can receive the electric energy through the charge-discharge module, thereby achieving the equalization of the electric quantity between the two parts of battery cells in the battery pack, effectively avoiding the overcharge or overdischarge of part of the battery cells in the battery pack, and thus improving the stability and reliability of the battery management system.

[0035] To achieve the above object, the vehicle of the fifth aspect of the present disclosure comprises: a battery pack comprising a plurality of battery cells connected in series, and a connection point between adjacent two battery cells; and the battery management system described in the above embodiments, which is connected to the battery pack.

[0036] According to the vehicle of the present disclosure, by adopting the battery management system described in the above embodiments, the electric energy can be effectively transferred between the two parts of battery cells divided by the target connection point, the equalization of the electric quantity between the two parts of battery cells in the battery pack is achieved, the overcharge or overdischarge of part of the battery cells in the battery pack is effectively avoided, and thus the service life of the battery pack is improved, and the overall performance of the vehicle is improved.

[0037] Additional aspects and advantages of the present disclosure will be in part apparent and in part pointed out hereinafter in the description of embodiments. BRIEF DESCRIPTION OF DRAWINGS

[0038] The above and / or additional aspects and advantages of the present disclosure will become apparent and be readily appreciated from the description of embodiments, taken in conjunction with the following drawings in which:

[0039] FIG. 1 is a schematic diagram of an equalization circuit according to one embodiment of the present disclosure;

[0040] FIG. 2 is a schematic diagram of an equalization circuit according to another embodiment of the present disclosure;

[0041] FIG. 3 is a schematic diagram of an equalization circuit according to another embodiment of the present disclosure;

[0042] FIG. 4 is a flowchart of an equalization circuit according to an embodiment of the present disclosure;

[0043] FIG. 5 is a schematic diagram of current flow during equalization when the actual voltage at the target connection point is less than the desired voltage according to an embodiment of the present disclosure;

[0044] FIG. 6 is a schematic diagram of current flow during equalization when the actual voltage at the target connection point is greater than the desired voltage according to an embodiment of the present disclosure;

[0045] FIG. 7 is a block diagram of an electronic device according to an embodiment of the present disclosure;

[0046] FIG. 8 is a block diagram of a battery management system according to an embodiment of the present disclosure;

[0047] FIG. 9 is a block diagram of a vehicle according to an embodiment of the present disclosure.

[0048] Reference signs: vehicle 100; battery management system 1; battery pack 2; battery cell 3; equalization circuit 10; acquisition circuit 20; charge and discharge module 11; switch module 12; controller 13; first inductor 111; first switch 112; first diode 113; second inductor 114; second switch 115; second diode 116; first contact 121; second contact 122; controllable switch element 123; third switch 124; electronic device 200; processor 201; memory 202. DETAILED DESCRIPTION

[0049] Embodiments of the present disclosure are described in detail below with reference to the accompanying drawings. The embodiments described with reference to the accompanying drawings are exemplary.

[0050] In related art, during use of a battery pack, due to small differences between battery cells, such as unmatched internal resistance, capacity differences, etc., some battery cells may charge or discharge faster than other battery cells, leading to energy imbalance between battery cells in the battery pack. Embodiments of the present disclosure propose an equalization circuit that can achieve equalization of the battery pack, effectively avoiding overcharging or over-discharging of some battery cells in the battery pack, thereby improving the service life and energy utilization efficiency of the battery pack.

[0051] In some embodiments, the battery pack can include a plurality of battery cells connected in series, with a connection point between each two adjacent battery cells. For example, if the number of battery cells is n, then the number of connection points is n-1, where n≥2. Through these connection points, the system can monitor the voltage information of each battery cell in real time, thereby obtaining the state information of each battery cell in the battery pack.

[0052] In some embodiments, the battery cells can be various types of batteries, including but not limited to lithium-ion batteries, nickel-hydrogen batteries, lead-acid batteries, and lithium iron phosphate batteries, etc.

[0053] The equalization circuit according to embodiments of the present disclosure is described below with reference to FIGS. 1 and 2.

[0054] FIGS. 1-2 are schematic diagrams of an equalization circuit according to one embodiment of the present disclosure. As shown in FIGS. 1-2, the equalization circuit 10 includes a charge-discharge module 11, a switch module 12, and a controller 13.

[0055] In some embodiments, the charge-discharge module 11 can be a device that transfers electrical energy between different parts of the battery cells 3. It can achieve charging and discharging of the battery cells 3 by controlling the direction of current flow, thereby balancing the electrical quantity of each part of the battery cells 3 in the battery pack 2.

[0056] In some embodiments, the charge-discharge module 11 can include three power transmission endpoints, namely an upper power transmission endpoint, a lower power transmission endpoint, and a middle power transmission endpoint. These power transmission endpoints can be used to transmit energy and control current flow. The upper power transmission endpoint is the first end of the charge-discharge module 11, the lower power transmission endpoint is the second end of the charge-discharge module 11, and the middle power transmission endpoint is the third end of the charge-discharge module 11.

[0057] In some embodiments, the first end of the charge-discharge module 11 is connected to the positive terminal of the battery pack 2, and the second end of the charge-discharge module 11 is connected to the negative terminal of the battery pack 2, for controlling the on-off of the target charge-discharge channel.

[0058] In some embodiments, the switch module 12 can be a multi-channel switch matrix for controlling the path of energy transmission and current flow. It has multiple input ends and one output end, and by controlling the connection state of the input ends, one of the input ends can be selected to be connected to the output end.

[0059] As shown in FIGS. 1-2, the first end of the switch module 12 is connected to each connection point, and the second end of the switch module 12 is connected to the third end (middle power transmission endpoint) of the charge-discharge module 11, for controlling the connection of the target connection point to the third end of the charge-discharge module 11.

[0060] In some embodiments, the target connection point can be the connection point most in need of balancing operation. By connecting the first end of the switch module 12 to the target connection point and connecting the second end of the switch module 12 to the third end of the charge-discharge module 11, the battery pack 2 can be divided into two parts, i.e. the battery cells 3 in the upper part and the battery cells 3 in the lower part, with the target connection point as the dividing line. Among them, the battery cells 3 in the upper part are the battery cells 3 between the target connection point and the positive end of the battery pack 2, and the battery cells 3 in the lower part are the battery cells 3 between the target connection point and the negative end of the battery pack 2.

[0061] In some embodiments, the controller 13 can be a variety of types of controllers, including but not limited to: microcontrollers, digital signal processors, and programmable logic controllers, etc. The controller 13 is connected to the charge-discharge module 11 and the switch module 12, and is used to determine the target connection point according to the total voltage of the battery pack 2 and the actual voltage at each connection point, control the switch module 12 according to the target connection point, and control the charge-discharge module 11 according to the actual voltage at the target connection point, so that the battery cells 3 in the two parts of the battery pack 2 divided by the target connection point are charged and discharged.

[0062] Specifically, taking the negative end of the battery pack 2 as the voltage reference zero point, the controller 13 can monitor the total voltage of the battery pack 2 and the actual voltage at each connection point through the voltage sensor. Based on the collected voltage data, the connection point most in need of balancing operation can be found, and the controller 13 can set this connection point as the target connection point.

[0063] Further, after determining the target connection point, the controller 13 can send a control signal to the switch module 12, and the switch module 12 performs a switch selection action to connect its first end to the target connection point after receiving the control signal. In this way, a channel is formed between the target connection point and the charge-discharge module 11. This channel divides the battery pack 2 into two parts, i.e. the battery cells 3 in the upper part and the battery cells 3 in the lower part. At the same time, the charge-discharge module 11 is also divided into two "energy transfer" sub-modules, and the third end of the charge-discharge module 11 is the common end of the two sub-modules.

[0064] Further, the controller 13 can control the two "energy transfer" sub-modules of the charge-discharge module 11 to perform corresponding operations according to the actual voltage at the target connection point. For example, the "energy transfer" sub-module located in the upper part can transfer the energy of the battery cells 3 in the upper part to the battery cells 3 in the lower part, and the "energy transfer" sub-module located in the lower part can transfer the energy of the battery cells 3 in the lower part to the battery cells 3 in the upper part. The charge-discharge module 11 is controlled by an external PWM driving signal, and can realize the function of continuous energy transfer.

[0065] Therefore, through the control operation of the controller 13, the charge-discharge module 11 can realize the effective transfer of electric energy between the battery monomers 3 on both sides of the target connection point, thereby realizing the balancing of the electric energy of the battery pack 2, avoiding overcharging or over-discharging of some battery monomers 3, and improving the service life and performance of the battery pack 2.

[0066] According to the balancing circuit 10 of the embodiment of the present disclosure, the controller 13 can determine the target connection point by monitoring the total voltage of the battery pack 2 and the actual voltage at each connection point in real time, which can be the point most in need of balancing operation, and divide the battery pack 2 into two parts as a demarcation line. When the target connection point is determined, the controller 13 can send instructions to the switch module 12 to connect the target connection point with the charge-discharge module 11. At the same time, the controller 13 controls the charge-discharge module 11 according to the actual voltage at the target connection point, so that the battery monomers 3 divided by the target connection point in the battery pack 2 perform charge-discharge operation, that is, when some battery monomers 3 perform discharge operation, the other battery monomers 3 can receive the electric energy through the charge-discharge module 11, thereby completing the balancing cycle of discharging to charging of the battery pack 2. Through such a circuit structure, energy can be effectively transferred between the battery monomers 3 divided by the target connection point, realizing the balancing of the electric energy between the two parts of the battery monomers 3 in the battery pack 2, effectively avoiding the overcharging or over-discharging of some batteries in the battery pack 2, thereby improving the service life and performance of the battery pack 2. Moreover, the circuit structure is simple and the cost is low.

[0067] As shown in FIG. 1, the charge-discharge module 11 includes a first inductor 111. In the balancing circuit 10, the first inductor 111 can store and release energy through its electromagnetic properties. The first end of the first inductor 111 is connected with the positive terminal of the battery pack 2, and the second end of the first inductor 111 is connected with the second end of the switch module 12, for charge-discharge when the actual voltage at the target connection point is less than the expected voltage.

[0068] The expected voltage can be set according to the total voltage of the battery pack 2 and the number of battery monomers 3, reflecting the voltage value that each connection point should reach in the ideal balancing state. The expected voltage can be used to guide the balancing control, judge the direction of energy transfer, and ensure that the voltages of the battery monomers 3 in each part of the battery pack 2 tend to be balanced. For example, if the actual voltage at the target connection point is less than the expected voltage, the controller 13 controls to open the “energy transfer” submodule located above, and transfers the energy of the battery monomers 3 located above to the battery monomers 3 located below, so that the voltage of the target connection point slowly rises to gradually approach the expected value.

[0069] Specifically, when the actual voltage at the target connection point is less than the desired voltage, all the battery cells 3 between the target connection point and the positive terminal of the battery pack 2 can release electric energy. When there is current passing through the first inductor 111 in the circuit, the first inductor 111 can generate a magnetic field inside and store the electric energy as magnetic energy. When the current stops, the first inductor 111 can release the stored magnetic energy, convert it into electric energy, and then deliver the electric energy to the battery cells 3 between the target connection point and the negative terminal of the battery pack 2, so that the actual voltage at the target connection point gradually increases to gradually approach the desired voltage.

[0070] Therefore, in this way, the first inductor 111 can effectively transfer energy between different parts of the battery pack 2 to balance the voltage. This energy transfer can avoid overcharging or over-discharging of some battery cells 3 in the battery pack 2, thereby improving the overall performance and service life of the battery pack 2.

[0071] As shown in FIG. 1, the charge and discharge module 11 further includes a first switch 112. The first end of the first switch 112 is connected to the positive terminal of the battery pack 2, and the second end of the first switch 112 is connected to the first end of the first inductor 111, for conducting when the actual voltage at the target connection point is less than the desired voltage, and for opening when the current passing through the target connection point reaches the current threshold.

[0072] Specifically, when the actual voltage at the target connection point is less than the desired voltage, the first switch 112 conducts, and the battery cells 3 between the target connection point and the positive terminal of the battery pack 2 can release electric energy. When there is current passing through the first inductor 111 in the circuit, the first inductor 111 can generate a magnetic field inside and store the electric energy as magnetic energy; when the current passing through the target connection point reaches the current threshold, the first switch 112 is opened, at which time the battery cells 3 between the target connection point and the positive terminal of the battery pack 2 cannot continue to release electric energy. The first inductor 111 can release the stored magnetic energy, convert it into electric energy, and then deliver the electric energy to the battery cells 3 between the target connection point and the negative terminal of the battery pack 2, so that the actual voltage at the target connection point gradually increases to gradually approach the desired voltage.

[0073] In some embodiments, the current threshold can be a set value that the current flowing through the target connection point reaches. When the current exceeds this threshold, the first switch 112 will automatically turn off to prevent excessive current from damaging the battery cell 3. The setting of the current threshold can take into account factors such as the rated current, operating temperature, and safety of the battery cell 3. The current threshold can be set within the safe operating range of the battery cell 3 to ensure the safety and stability of the battery pack 2. By setting and controlling the current threshold parameter, the first switch 112 can effectively protect the safety of the battery pack 2 and ensure the smooth progress of the balancing operation, thereby prolonging the service life of the battery pack 2 and improving its performance.

[0074] As shown in FIG. 1, the charge and discharge module 11 further includes a first diode 113. The first diode 113 is a unidirectional conduction element that allows current to flow in one direction and prevents current from flowing in the opposite direction to protect other components in the circuit. In addition, the first diode 113 provides a discharge path during the discharge phase of the first inductor 111. When the first switch 112 is turned off, the current in the first inductor 111 cannot be instantaneously stopped due to the inductive property, and the first diode 113 can provide a path for the current in the first inductor 111 to continue to flow, avoiding damage to the circuit caused by voltage surges. Therefore, the first diode 113 ensures the safety and effectiveness of the balancing control process, helping to achieve energy transfer and voltage balancing between the battery cells 3.

[0075] In some embodiments, the anode end of the first diode 113 is connected to the negative end of the battery pack 2, and the cathode end of the first diode 113 is connected to the first end of the first inductor 111 and the second end of the first switch 112. This connection ensures that during the first inductor discharge process, current can only flow from the first inductor 111 to the negative end of the battery pack 2 and cannot flow in the opposite direction, protecting the battery pack 2 and other circuit components.

[0076] As shown in FIG. 1, the charge-discharge module 11 further comprises a second inductor 114. In the equalization circuit 10, the second inductor 114 can store and release energy through its electromagnetic properties. The first end of the second inductor 114 is connected to the negative terminal of the battery pack 2, and the second end of the second inductor 114 is connected to the second end of the first inductor 111 and the second end of the switch module 12, for charging and discharging when the actual voltage at the target connection point is greater than the expected voltage. The expected voltage can be used to guide the equalization control, determine the direction of energy transfer, and ensure that the voltages of the battery cells 3 in the battery pack 2 tend to be equalized. For example, if the actual voltage at the target connection point is greater than the expected voltage, the controller 13 controls the "energy transfer" submodule below to transfer the energy of the battery cells 3 below the target connection point to the battery cells 3 above the target connection point, so that the voltage at the target connection point gradually decreases to gradually approach the expected value.

[0077] Specifically, when the actual voltage at the target connection point is greater than the expected voltage, the battery cells 3 between the target connection point and the negative terminal of the battery pack 2 can release electrical energy. When there is a current passing through the second inductor 114 in the circuit, the second inductor 114 can generate a magnetic field inside it and convert the electrical energy into magnetic energy for storage; when the current stops, the second inductor 114 can release the stored magnetic energy and convert it into electrical energy, and then deliver the electrical energy to the battery cells 3 between the target connection point and the positive terminal of the battery pack 2, so that the actual voltage at the target connection point gradually decreases to gradually approach the expected voltage.

[0078] Therefore, by adding the second inductor 114 and transferring energy when the actual voltage is greater than the expected voltage, the equalization circuit 10 can effectively adjust the voltage difference between the battery cells 3 and achieve equalization control. This not only improves the service life and performance of the battery pack 2, but also ensures the safe operation of the battery cells 3.

[0079] As shown in FIG. 1, the charge-discharge module 11 further comprises a second switch 115. The first end of the second switch 115 is connected to the negative terminal of the battery pack 2, and the second end of the second switch 115 is connected to the first end of the second inductor 114, for conducting when the actual voltage at the target connection point is greater than the expected voltage, and for opening when the current flowing through the target connection point reaches the current threshold.

[0080] Specifically, when the actual voltage at the target connection point is greater than the desired voltage, the second switch 115 is turned on, and the battery cell 3 between the target connection point and the negative terminal of the battery pack 2 can release electrical energy. When there is current flowing through the second inductor 114 in the circuit, the second inductor 114 can generate a magnetic field inside it and convert electrical energy into magnetic energy for storage; when the current flowing through the target connection point reaches the current threshold, the second switch 115 is turned off, at which time the battery cell 3 between the target connection point and the negative terminal of the battery pack 2 cannot continue to release electrical energy. The second inductor 114 can release the stored magnetic energy, convert it into electrical energy, and then deliver the electrical energy to the battery cell 3 between the target connection point and the positive terminal of the battery pack 2, thereby causing the actual voltage at the target connection point to slowly decrease to gradually approach the desired voltage.

[0081] As shown in FIG. 1, the charge and discharge module 11 further includes a second diode 116. The second diode 116 can also be a unidirectional conduction element that allows current to flow in one direction and prevents current from flowing in the opposite direction to protect other components in the circuit. In addition, the second diode 116 provides a discharge path during the discharge phase of the second inductor 114. When the second switch 115 is turned off, the current in the second inductor 114 cannot be stopped instantaneously due to the inductive property, and the second diode 116 can provide a path for the current in the second inductor 114 to continue to flow, avoiding damage to the circuit caused by voltage surges. Thus, the second diode 116 ensures the safety and effectiveness of the balancing control process and helps achieve energy transfer and voltage balancing among the battery cells 3.

[0082] In some embodiments, the anode terminal of the second diode 116 is connected to the first terminal of the second inductor 114 and the second terminal of the second switch 115, and the cathode terminal of the second diode 116 is connected to the positive terminal of the battery pack 2. This connection ensures that during the discharge process of the second inductor, current can only flow from the second inductor 114 to the positive terminal of the battery pack 2 and cannot flow in the opposite direction. The battery cell 3 between the target connection point and the positive terminal of the battery pack 2 can act as a load to receive the energy released from the second inductor 114, thereby achieving voltage balancing and protecting the battery pack 2 and circuit components.

[0083] In some embodiments, the first switch 112 and the second switch 115 are both high-frequency unidirectional electronic switches. The high-frequency unidirectional electronic switch can be a switching device capable of operating at high frequencies, such as tens of kilohertz to several megahertz. Such switching devices can complete the turn-on and turn-off actions in a short time, with high response speed and switching frequency.

[0084] In some embodiments, the high-frequency unidirectional electronic switch can only allow current to flow in one direction, similar to the characteristics of a diode. This unidirectionality is used in circuit design to control the direction of current flow and prevent reverse current from damaging the circuit.

[0085] Therefore, by adopting the high-frequency unidirectional electronic switch, the balancing circuit 10 can achieve more efficient and safer energy management and voltage balancing. The first switch 112 and the second switch 115, under the precise control of the controller 13, ensure the efficient transfer of energy between the battery cells 3, improving the performance and life of the battery pack 2. High-frequency operation reduces energy loss, and the unidirectional characteristic protects the circuit, and the fast response of the electronic switch improves the efficiency and stability of the balancing operation.

[0086] In some embodiments, the switch module 12 includes a plurality of first contacts 121, a second contact 122, and a controllable switching element 123. Among them, the plurality of first contacts 121 can be a plurality of power transmission endpoints for transmitting energy and controlling current flow. The plurality of first contacts 121 are respectively connected with the plurality of connection points. For example, the first end of the switch module 12 can include n-1 first contacts 121, which can be respectively connected with n-1 connection points in the battery pack 2, where n≥2.

[0087] In some embodiments, the second contact 122 can be a power transmission endpoint for transmitting energy and controlling current flow. The second contact 122 is connected with the third end of the charge-discharge module 11. For example, the second end of the switch module 12 can include 1 second contact 122, which is connected with the third end (middle power transmission endpoint) of the charge-discharge module 11, for controlling the target connection point to be connected with the third end of the charge-discharge module 11.

[0088] In some embodiments, the first end of the controllable switching element 123 is connected with the second contact 122, the control end of the controllable switching element 123 is connected with the controller 13, and the second end of the controllable switching element 123 is connected with the first contact 121 connected with the target connection point in response to the balancing instruction of the controller 13.

[0089] Therefore, the role of the switch module 12 is to select the target connection point that needs to be balanced according to the instruction of the controller 13, and connect the target connection point with the charge-discharge module 11 through the controllable switching element 123, so as to realize the energy transfer and voltage balancing between the two parts of the battery cells 3 divided by the target connection point.

[0090] FIG. 3 is a schematic diagram of the equalization circuit 10 according to another embodiment of the present disclosure. As shown in FIG. 3, the switch module 12 further comprises a plurality of third switches 124. The first ends of the plurality of third switches 124 are connected to the plurality of connection points one by one, the second ends of the plurality of third switches 124 are all connected to the third end of the charge and discharge module 11, and the control end of each third switch 124 is connected to the controller 13. In response to the equalization instruction of the controller 13, the third switch 124 connected to the target connection point is closed. That is, when the voltage of a certain connection point is too high or too low, the controller 13 can select the corresponding third switch 124 to be closed according to the situation, so as to transfer the current from the side with higher voltage to the side with lower voltage in the two parts divided by the target connection point, so as to realize the voltage equalization between the two parts of battery monomers 3, thereby maintaining the stability of the entire battery pack 2.

[0091] In some embodiments, the third switch 124 can be a low-frequency bidirectional electronic switch. The low-frequency bidirectional electronic switch has a lower cost and is suitable for mass production. In addition, the number of third switches 124 in the switch module 12 corresponds to the number of connection points in the battery pack 2, so as to ensure that each connection point has a corresponding channel for equalization operation.

[0092] The battery equalization method according to an embodiment of the present disclosure is described below with reference to FIG. 4, which is used in the equalization circuit 10 described in the above embodiments.

[0093] FIG. 4 is a flowchart of the equalization circuit according to an embodiment of the present disclosure. As shown in FIG. 4, the battery equalization method at least comprises steps S1-S3, which are specifically as follows:

[0094] S1, determining a target connection point according to the total voltage of the battery pack and the actual voltage at the connection point between each two adjacent battery monomers.

[0095] In some embodiments, the target connection point is the connection point with the largest absolute value of the voltage difference between the expected voltage and the actual voltage among the plurality of connection points of the battery pack, wherein the expected voltage is the voltage of the connection point in the equalization state of the battery pack.

[0096] In some embodiments, the expected voltage is the product value of the average voltage of the plurality of battery monomers in the battery pack and the sequential number of the connection point, wherein the negative electrode end of the battery pack is taken as the zero potential point, and the connection point between the first battery monomer and the second battery monomer on the side of the negative electrode end of the battery pack is taken as the first connection point. The second connection point is the connection point between the second battery monomer and the third battery monomer, and so on.

[0097] Specifically, the AFE (Analog Front End) module can be used to measure the actual voltage value of each connection point in real time. For example, each connection point can be J(1), J(2), …, J(i+1) from the negative end to the positive end. The AFE module is a component for signal processing, which is mainly used to receive analog signals from sensors or other input devices, and perform amplification, filtering, analog-to-digital conversion, etc. on these signals. In the battery management system (BMS, Battery Management System), the AFE module is responsible for measuring the voltage and other parameters of each battery monomer, and then converting these analog signals into digital signals, which are transmitted to the microcontroller (MCU, Microcontroller Unit) for further processing and control.

[0098] Further, the MCU software can calculate the average voltage value of each battery monomer, and the specific calculation formula is as follows:

[0099] V avg = V J(i+1) / i;

[0100] Where i represents the total number of battery monomers in series, V avg represents the average voltage value, and V J(i+1) represents the actual voltage value of J(i+1) connection point, which is the total voltage of the battery pack. For example, if there are 5 battery monomers in the battery pack, and the total voltage of the battery pack is 20V, then the average voltage value of each connection point is 4V.

[0101] Further, the MCU software can calculate the expected voltage of each connection point when the battery monomer voltage is balanced, and the specific calculation formula is as follows:

[0102] V p(n) = V avg ×n(n=1, 2, …, i);

[0103] Where n represents the sequential number of the connection point, V avg represents the average voltage value, and V p(n) represents the expected voltage value of the nth connection point. For example, if there are 5 battery monomers in the battery pack, and the total voltage of the battery pack is 20V, then the average voltage value of each connection point is 4V. The expected voltage value of the first connection point (n=1) is 4V, the expected voltage value of the second connection point (n=2) is 8V, the expected voltage value of the third connection point (n=3) is 12V, the expected voltage value of the fourth connection point (n=4) is 16V, and the expected voltage value of the fifth connection point (n=5) is 20V.

[0104] Further, the MCU software can calculate the absolute value of the voltage difference between the expected voltage value and the actual voltage value of each connection point, and the specific calculation formula is as follows:

[0105] V e(n) = |V J(n) -V p(n) |;

[0106] wherein V e(n) represents the absolute value of the voltage difference between the actual voltage value and the expected voltage value of the nth connection point, V J(n) represents the actual voltage value of the nth connection point, and V p(n) represents the expected voltage value of the nth connection point.

[0107] Further, the MCU software can find the connection point order number n with the maximum value V e(n)-max of the absolute value of the voltage difference between the actual voltage and the expected voltage, and compare the size of V e(n)-max and the minimum threshold value V th-min of the equalization starting voltage. The minimum threshold value of the equalization starting voltage can refer to the voltage difference threshold value used to determine whether to start the equalization operation in the battery equalization control process. The minimum threshold value of the equalization starting voltage actually reflects the tolerance of the system to the actual voltage error of the battery monomer.

[0108] When the minimum threshold value of the equalization starting voltage is set to be large, the tolerance of the system to the error between the actual voltage and the expected voltage is high. That is, there can be a large voltage difference between the battery monomers without performing the equalization operation. Only when the voltage difference exceeds this larger threshold value, the system will start the equalization. When the minimum threshold value of the equalization starting voltage is set to be small, the tolerance of the system to the error between the actual voltage and the expected voltage is low, that is, when there is a small voltage difference between the battery monomers 3, the system can start the equalization operation.

[0109] Further, if the maximum value V e(n)-max of the absolute value of the voltage difference between the actual voltage and the expected voltage is less than the minimum threshold value V th-min of the equalization starting voltage, the current cycle time is waited to be consumed, and then the change of the connection point voltage is continuously monitored in real time. If the maximum value V e(n)-max of the absolute value of the voltage difference between the actual voltage and the expected voltage is greater than or equal to the minimum threshold value V e(n)-max of the equalization starting voltage, it is judged whether the current connection point being executed the equalization control is the connection point n (target connection point), if not, the equalization control of the current connection point is stopped. Then, the equalization control is started for the connection point n; if the current connection point is the connection point n, the equalization control of the connection point n is continuously performed.

[0110] S2, controlling the switch module of the equalization circuit according to the target connection point, so that the target connection point is connected with the charge-discharge module of the equalization circuit.

[0111] Specifically, for example, referring to FIG. 1-3, after determining the target connection point, the controller 13 can send a control signal to the switch module 12, and after receiving the control signal, the switch module 12 performs a switch selection action (in FIG. 1, the second end of the controllable switch is connected with the first contact 121 of the target connection point, or in FIG. 3, the target connection point is connected with the first end of the corresponding third switch 124). The second end of the switch module 12 (the second contact 122 in FIG. 1, or the second end of the third switch 124 in FIG. 3) is connected with the third end of the charge-discharge module 11, so that the target connection point is connected with the charge-discharge module 11 of the equalization circuit 10. In this way, a channel is formed between the target connection point and the charge-discharge module 11. The channel divides the battery pack 2 into two parts, the battery cells 3 in the upper part and the battery cells 3 in the lower part. At the same time, the charge-discharge module 11 is also divided into two "energy transfer" sub-modules, and the third end of the charge-discharge module 11 is the common end of the two sub-modules.

[0112] S3, controlling the charge-discharge module according to the actual voltage at the target connection point, so that the battery cells 3 in the two parts divided by the target connection point in the battery pack are charged and discharged.

[0113] Specifically, the basic principle of the battery equalization method of the embodiments of the present disclosure is to realize energy transfer in the process of equalization control. That is, for the battery cells in the two parts divided by the target connection point, a part of the battery cells can be controlled to discharge, and the electrical energy is converted into magnetic energy and stored in the inductor of the charge-discharge module. Then, the inductor releases the magnetic energy, and the magnetic energy is converted into electrical energy and stored in another part of the battery cells. The charge-discharge module is controlled by an external PWM driving signal, and the continuous energy transfer function can be realized.

[0114] According to the battery equalization method, the total voltage of the battery pack and the actual voltage at the connection point between every two adjacent battery cells are monitored in real time, so that the target connection point, which is the point most in need of equalization operation, can be determined, and the battery pack is divided into two parts as a demarcation line. After the target connection point is determined, the switch module of the equalization circuit is controlled according to the target connection point, so that the target connection point is connected to the charge-discharge module. At the same time, the controller 13 controls the charge-discharge module according to the actual voltage at the target connection point, so that the two parts of battery cells divided by the target connection point in the battery pack are subjected to charge-discharge operation. That is, when a part of the battery cells is subjected to discharge operation, another part of the battery cells can receive the electric energy through the charge-discharge module, thereby completing the equalization cycle of discharging to charging of the battery pack. Through this method, the energy can be effectively transferred between the two parts of battery cells divided by the target connection point, the electric quantity between the two parts of battery cells in the battery pack is equalized, the overcharging or overdischarging of part of the battery cells in the battery pack 2 is avoided, and thus the service life and performance of the battery pack are improved.

[0115] In some embodiments, controlling the charge-discharge module according to the actual voltage at the target connection point comprises: when the actual voltage at the target connection point is less than the expected voltage, controlling the first switch of the charge-discharge module to be closed, so that the battery cells between the target connection point and the positive electrode end of the battery pack 2 are discharged.

[0116] Specifically, when the controller 13 monitors that the actual voltage at the target connection point is less than the expected voltage, an equalization instruction can be sent to the switch module to control the third switch connected to the target connection point to be closed. After the third switch is closed and stabilized, the first switch of the charge-discharge module is controlled to be closed, so that the multiple series-connected battery cells in the upper part of the two parts of battery cells 3 divided by the target connection point (i.e., the battery cells between the target connection point and the positive electrode end of the battery pack) start discharging along the loop composed of the target connection point, the third switch connected to the target connection point, the first inductor and the first switch. The initial current value of the first inductor is zero ampere, and since the inductive current cannot jump, the current gradually increases from zero, and the electric energy can be converted into magnetic energy and stored in the first inductor.

[0117] In some embodiments, controlling the charge-discharge module according to the actual voltage at the target connection point further comprises: when the current flowing through the target connection point reaches a current threshold, controlling the first switch to be opened, so as to charge the battery cells between the target connection point and the negative electrode end of the battery pack.

[0118] Specifically, when the current flowing through the target connection point reaches the current threshold, the first switch is controlled to be turned off, and the loop composed of the target connection point, the third switch connected to the target connection point, the first inductor and the first switch is disconnected. The first inductor can release the stored magnetic energy and convert it into electrical energy. Since the inductive current cannot jump, the current released by the first inductor will continue to flow along the loop composed of the third switch connected to the target connection point, the first diode and the first inductor. The current will be transmitted to the multiple series-connected battery cells in the lower part of the two parts of the battery cells divided by the target connection point (i.e., the battery cells between the target connection point and the negative terminal of the battery pack in the battery pack) to charge.

[0119] Further, after the first inductor is discharged, the current gradually decreases, and when the current decreases to zero ampere, the first inductor is fully discharged, thereby completing one equalization cycle of discharging the battery cells between the target connection point and the positive terminal of the battery pack in the battery pack to the battery cells between the target connection point and the negative terminal of the battery pack in the battery pack.

[0120] Further, after completing one equalization cycle, the controller 13 can start to perform the equalization cycle process again to monitor the voltage changes of each connection point to maintain the voltage balance state of the connection points. In each equalization cycle, the flow direction of the current changes as shown in FIG. 5.

[0121] In some embodiments, the charging and discharging module is controlled according to the actual voltage at the target connection point, including: when the actual voltage at the target connection point is greater than the expected voltage, the second switch of the charging and discharging module is controlled to be turned on, so that the battery cells between the target connection point and the negative terminal of the battery pack in the battery pack are discharged.

[0122] Specifically, when the controller 13 monitors that the actual voltage at the target connection point is less than the expected voltage, an equalization instruction can be sent to the switch module to control the third switch connected to the target connection point to be turned on. After waiting for the third switch to be stable, the second switch of the charging and discharging module is controlled to be turned on, so that the multiple series-connected battery cells in the lower part of the two parts of the battery cells divided by the target connection point (i.e., the battery cells between the target connection point and the negative terminal of the battery pack in the battery pack) start to be discharged along the loop composed of the target connection point, the third switch connected to the target connection point, the second inductor and the second switch. The initial current value of the second inductor is zero ampere, and since the inductive current cannot jump, the current gradually increases from zero, and the electrical energy can be converted into magnetic energy and stored in the second inductor.

[0123] In some embodiments, the charging and discharging module is controlled according to the actual voltage at the target connection point, further including: when the current flowing through the target connection point reaches the current threshold, the second switch is controlled to be turned off to charge the battery cells between the target connection point and the positive terminal of the battery pack in the battery pack 2.

[0124] Specifically, when the current flowing through the target connection point reaches the current threshold, the second switch is controlled to be turned off, and the loop composed of the target connection point, the third switch connected to the target connection point, the second inductor and the second switch is disconnected. The second inductor can release the stored magnetic energy into electrical energy. Since the inductive current cannot jump, the current released by the second inductor will continue to flow along the loop composed of the third switch connected to the target connection point, the second diode and the second inductor. The current will be transmitted to the multiple series-connected battery cells 3 in the upper part of the battery cells divided by the target connection point (i.e., the battery cells 3 between the target connection point and the positive terminal of the battery pack in the battery pack 2) to charge.

[0125] Further, after the second inductor is discharged, the current gradually decreases, and when the current decreases to zero ampere, the second inductor is fully discharged, thereby completing one equalization cycle of discharging the battery cells between the target connection point and the negative terminal of the battery pack 2 in the battery pack to charging the battery cells between the target connection point and the positive terminal of the battery pack in the battery pack.

[0126] Further, after completing one equalization cycle, the controller 13 can start to perform the equalization cycle process again to monitor the voltage changes of each connection point to maintain the voltage equalization state of the connection points. In each equalization cycle, the current flow direction changes as shown in FIG. 6.

[0127] In summary, the battery equalization method of the embodiment of the present disclosure is divided into two cases, one case is that the actual voltage value at the target connection point is greater than the expected voltage value, and the other case is that the actual voltage value at the target connection point is less than the expected voltage value. When the actual voltage value at the target connection point is greater than the expected voltage value, the target connection point can be discharged to slowly decrease the voltage of the target connection point to achieve the purpose of equalization; when the actual voltage value at the target connection point is less than the expected voltage value, the target connection point can be charged to slowly increase the voltage of the target connection point to achieve the purpose of equalization.

[0128] The electronic device 200 according to the embodiment of the present disclosure is described below with reference to FIG. 7.

[0129] FIG. 7 is a block diagram of the electronic device 200 according to one embodiment of the present disclosure, as shown in FIG. 7, the electronic device 200 includes a memory 202 and at least one processor 201.

[0130] The at least one processor 201 can be one processor 201, two processors 201, three processors 201, five processors 201, eight processors 201, ten processors 201, or the like. The processor 201 can be a general-purpose processor or a special-purpose chip, depending on the design and purpose of the electronic device 200.

[0131] In some embodiments, the memory 202 can be used to store computer programs and other necessary data. The memory 202 can include RAM (Random Access Memory) and ROM (Read-Only Memory), and the like. The computer program is stored in the memory 202 and waits for the processor 201 to execute.

[0132] In some embodiments, the memory 202 is in communication connection with the at least one processor 201, and the memory 202 stores a computer program executable by the at least one processor 201. The at least one processor 201 executes the computer program to implement the battery balancing method described in the above embodiments.

[0133] In some embodiments, the electronic device 200 can be any device that needs to manage the battery and balance the voltage, including but not limited to electric vehicles, energy storage devices, smart home devices, medical devices, and portable electronic devices (such as smartphones, tablets, and laptops), and the like.

[0134] According to the electronic device 200 of the embodiments of the present disclosure, by executing the computer program for implementing the battery balancing method described in the above embodiments, the energy can be effectively transferred between the two parts of the battery monomer 3 divided by the target connection point, the power balance of the two parts of the battery monomer 3 in the battery pack 2 is achieved, and the overcharging or overdischarging of part of the battery pack 2 is effectively avoided, thereby improving the service life and performance of the battery pack 2.

[0135] The battery management system 1 according to the embodiments of the present disclosure is described below with reference to FIG. 8.

[0136] FIG. 8 is a block diagram of the battery management system 1 according to one embodiment of the present disclosure. As shown in FIG. 8, the battery management system 1 includes a collection circuit 20 and a balancing circuit 10.

[0137] In some embodiments, the collection circuit 20 can be used to collect the total voltage of the battery pack 2 and the actual voltage at the connection point between each two adjacent battery monomers. The collection circuit 20 can include a voltage sensor and a signal processing unit. The voltage sensor can be used to measure the total voltage of the battery pack 2 and the actual voltage at the connection point between each two adjacent battery monomers. The signal processing unit can process the data collected by the voltage sensor and convert it into a form available to the system.

[0138] In some embodiments, the equalization circuit 10 is connected with the acquisition circuit 20, and controls the charge-discharge module 11 according to the voltage data provided by the acquisition circuit 20, so that the battery cells 3 in the two parts of the battery pack 2 divided by the target connection point are charged and discharged.

[0139] According to the battery management system 1 of the embodiments of the present disclosure, the acquisition circuit 20 is connected with the equalization circuit 10, the target connection point can be determined by acquiring the total voltage of the battery pack 2 and the actual voltage at the connection point between every two adjacent battery cells, which can be the point most needing equalization operation, and the battery pack 2 is divided into two parts as a demarcation line, the switch module 12 of the equalization circuit 10 is controlled according to the target connection point, so that the target connection point is connected with the charge-discharge module 11 of the equalization circuit 10, the charge-discharge module 11 is controlled according to the actual voltage at the target connection point, so that the battery cells in the two parts of the battery pack 2 divided by the target connection point are charged and discharged, that is, when the battery cells in one part are discharged, the battery cells in the other part can receive the electric energy through the charge-discharge module 11, thereby realizing the equalization of the electric quantity of the battery cells in the two parts of the battery pack 2, effectively avoiding the overcharging or overdischarging of the battery cells in the battery pack 2, and improving the stability and reliability of the battery management system 1.

[0140] Next, the vehicle 100 according to the embodiments of the present disclosure is described with reference to FIG. 9.

[0141] FIG. 9 is a block diagram of the vehicle 100 according to an embodiment of the present disclosure. As shown in FIG. 9, the vehicle 100 includes the battery pack 2 and the battery management system 1 described in the above embodiments.

[0142] In some embodiments, the battery pack 2 includes a plurality of battery cells connected in series. The battery cells can be various types of batteries, including but not limited to lithium-ion batteries, nickel-hydrogen batteries, lead-acid batteries, and lithium-iron-phosphate batteries, etc.

[0143] Among them, by connecting a plurality of battery cells in series, the total voltage of the battery pack 2 can be increased to meet the demand of high voltage of the equipment. For example, electric vehicles need higher voltage to drive the motor. In electric vehicles, hundreds of battery cells are connected in series to achieve hundreds of volts of working voltage to provide sufficient power output.

[0144] In some embodiments, there is a connection point between two adjacent battery cells. The connection point can refer to the electrical connection part between two adjacent battery cells, which is used for monitoring and control of the equalization circuit 10. Through these connection points, the equalization circuit 10 can obtain the voltage information of each battery cell in real time and perform corresponding voltage equalization control.

[0145] In some embodiments, the battery management system 1 is connected with the battery pack 2 for monitoring and managing the state of the battery pack 2, ensuring the safety and stability of the battery pack 2, and prolonging the service life of the battery pack 2.

[0146] In some embodiments, the vehicle 100 can be various types of vehicles 100, including but not limited to electric cars, hybrid cars, plug-in hybrid cars, electric bicycles, electric motorcycles, electric scooters, electric balance cars, electric wheelchairs, and the like.

[0147] According to the vehicle 100 of the embodiments of the present disclosure, by adopting the battery management system 1 described in the above embodiments, the effective transfer of electric energy between the two parts of the battery cells 3 divided by the target connection point can be controlled, the charge balance of the two parts of the battery cells 3 in the battery pack 2 is achieved, the overcharging or overdischarging of part of the battery cells in the battery pack 2 is effectively avoided, and thus the service life of the battery pack 2 is improved, and the overall performance of the vehicle 100 is improved.

[0148] In the description of the present specification, the description referring to the terms "one embodiment", "some embodiments", "illustrative embodiment", "example", "specific example", or "some examples" and the like means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present disclosure. In the present specification, the illustrative description of the above terms does not necessarily mean the same embodiment or example.

[0149] Although the embodiments of the present disclosure have been shown and described, it will be understood by those of ordinary skill in the art that various changes, modifications, replacements and variations of the embodiments can be made without departing from the principles and spirit of the present disclosure, and the scope of the present disclosure is defined by the claims and their equivalents.

Claims

1. An equalization circuit (10), characterized in that, For power balancing of a battery pack (2), the battery pack (2) includes multiple battery cells (3) connected in series, with a connection point between adjacent battery cells (3), and the balancing circuit (10) includes: A charging and discharging module (11) is provided, with its first end connected to the positive terminal of the battery pack (2) and its second end connected to the negative terminal of the battery pack (2), for controlling the opening and closing of the target charging and discharging channel. A switch module (12), the first end of which is connected to each of the connection points respectively, and the second end of which is connected to the third end of the charge / discharge module (11), for controlling the connection of the target connection point to the third end of the charge / discharge module (11); and A controller (13) is connected to the charging / discharging module (11) and the switch module (12) to determine the target connection point based on the total voltage of the battery pack (2) and the actual voltage at each connection point, control the switch module (12) based on the target connection point, and control the charging / discharging module (11) based on the actual voltage at the target connection point, so that the battery cells (3) in the battery pack (2) divided into two parts by the target connection point are charged and discharged.

2. The equalization circuit (10) according to claim 1, characterized in that, The charging and discharging module (11) includes: A first inductor (111) is connected at its first end to the positive terminal of the battery pack (2) and at its second end to the second end of the switch module (12), for charging and discharging when the actual voltage at the target connection point is less than the expected voltage.

3. The equalization circuit (10) according to claim 2, characterized in that, The charging and discharging module (11) also includes: A first switch (112) is connected at its first end to the positive terminal of the battery pack (2) and at its second end to the first end of the first inductor (111). The switch is used to conduct when the actual voltage at the target connection point is less than the desired voltage and to disconnect when the current flowing through the target connection point reaches a current threshold.

4. The equalization circuit (10) according to claim 3, characterized in that, The charging and discharging module (11) also includes: A first diode (113) is connected to the negative terminal of the battery pack (2), and the negative terminal of the first diode (113) is connected to the first terminal of the first inductor (111) and the second terminal of the first switch (112).

5. The equalization circuit (10) according to claim 4, characterized in that, The charging and discharging module (11) also includes: The second inductor (114) has its first end connected to the negative terminal of the battery pack (2), and the second end of the first inductor (111) is connected to the second end of the second inductor (114) and the second end of the switch module (12) for charging and discharging when the actual voltage at the target connection point is greater than the expected voltage.

6. The equalization circuit (10) according to claim 5, characterized in that, The charging and discharging module (11) also includes: The second switch (115) has its first end connected to the negative terminal of the battery pack (2) and its second end connected to the first end of the second inductor (114). It is used to conduct when the actual voltage at the target connection point is greater than the desired voltage and to disconnect when the current flowing through the target connection point reaches a current threshold.

7. The equalization circuit (10) according to claim 6, characterized in that, The charging and discharging module (11) also includes: The second diode (116) has its positive terminal connected to the first terminal of the second inductor (114) and the second terminal of the second switch (115), and its negative terminal connected to the positive terminal of the battery pack (2).

8. The equalization circuit (10) according to claim 6 or 7, characterized in that, Both the first switch (112) and the second switch (115) are high-frequency unidirectional electronic switches.

9. The equalization circuit (10) according to any one of claims 1-8, characterized in that, The switching module (12) includes: Multiple first contacts (121) are respectively connected to multiple connection points; The second contact (122) is connected to the third terminal of the charging / discharging module (11); and A controllable switch (123) is provided, wherein the first end of the controllable switch (123) is connected to the second contact (122), the control end of the controllable switch (123) is connected to the controller (13), and in response to the equalization command of the controller (13), the second end of the controllable switch (123) is connected to the first contact (121) connected to the target connection point.

10. The equalization circuit (10) according to any one of claims 1-9, characterized in that, The switching module (12) includes: Multiple third switches (124) are provided, with the first end of each of the multiple third switches (124) connected to a corresponding connection point, and the second end of each of the multiple third switches (124) connected to the third end of the charging and discharging module (11). The control end of each of the third switches (124) is connected to the controller (13). In response to the equalization command of the controller (13), the third switch (124) connected to the target connection point is closed.

11. The equalization circuit (10) according to claim 10, characterized in that, The third switch (124) is a low-frequency bidirectional electronic switch.

12. A battery balancing method, characterized in that, For the equalization circuit (10) according to any one of claims 1-11, the battery equalization method includes: The target connection point is determined based on the total voltage of the battery pack (2) and the actual voltage at the connection point between every two adjacent battery cells (3); The switching module (12) of the equalization circuit (10) is controlled according to the target connection point so that the target connection point is connected to the charging and discharging module (11) of the equalization circuit (10); and The charging and discharging module (11) is controlled according to the actual voltage at the target connection point so that the battery cells (3) in the battery pack (2) divided into two parts by the target connection point are charged and discharged.

13. The battery balancing method according to claim 12, characterized in that, The charging and discharging module (11) is controlled according to the actual voltage at the target connection point, including: When the actual voltage at the target connection point is less than the expected voltage, the first switch (112) of the charge / discharge module (11) is closed to allow the battery cells (3) between the target connection point and the positive terminal of the battery pack (2) to discharge.

14. The battery balancing method according to claim 13, characterized in that, The charging and discharging module (11) is controlled according to the actual voltage at the target connection point, and further includes: When the current flowing through the target connection point reaches the current threshold, the first switch (112) is controlled to open to charge the battery cell (3) between the target connection point and the negative terminal of the battery pack (2).

15. The battery balancing method according to claim 12 or 13, characterized in that, The charging and discharging module (11) is controlled according to the actual voltage at the target connection point, including: When the actual voltage at the target connection point is greater than the desired voltage, the second switch (115) of the charge / discharge module (11) is closed to allow the battery cells (3) between the target connection point and the negative terminal of the battery pack (2) to discharge.

16. The battery balancing method according to claim 15, characterized in that, The charging and discharging module (11) is controlled according to the actual voltage at the target connection point, and further includes: When the current flowing through the target connection point reaches the current threshold, the second switch (115) is controlled to open to charge the battery cell (3) between the target connection point and the positive terminal of the battery pack (2).

17. The battery balancing method according to any one of claims 12-16, characterized in that, The target connection point is the connection point with the largest absolute value of the voltage difference between the actual voltage and the expected voltage among the multiple connection points of the battery pack (2), wherein the expected voltage is the voltage of the connection point in the balanced state of the battery pack (2).

18. The battery balancing method according to claim 17, characterized in that, The desired voltage is the product of the average voltage of the multiple battery cells (3) in the battery pack (2) and the sequential number of the connection point, wherein the negative terminal of the battery pack (2) is taken as the zero potential point, and the connection point between the first battery cell (3) and the second battery cell (3) on the negative terminal side of the battery pack (2) is taken as the first connection point.

19. An electronic device (200), characterized in that, include: At least one processor (201); and The memory (202) is communicatively connected to the at least one processor (201). The memory (202) stores a computer program that can be executed by the at least one processor (201), and the at least one processor (201) implements the battery balancing method according to any one of claims 12-18 when executing the computer program.

20. A battery management system (1), characterized in that, include: The acquisition circuit (20) is used to acquire the total voltage of the battery pack (2) and the actual voltage at the connection point between every two adjacent battery cells (3); and The equalization circuit (10) according to any one of claims 1-11 is connected to the acquisition circuit (20).

21. A vehicle (100), characterized in that, include: A battery pack (2), comprising a plurality of battery cells (3) connected in series, with a connection point between adjacent battery cells (3); and The battery management system (1) according to claim 20 is connected to the battery pack (2).

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